chore: add blue theme (#362)

* doc: 增加一套 blue 主题

* test: test

* Update blue.css

* Update blue.css

* Update blue.css

Author: ArgoZhang

src/BootstrapBlazor.Shared/wwwroot/css/blue.css

@@ -0,0 +1,52 @@
+@media (min-width: 768px) {
+    .sidebar {
+        background-color: #fff !important;
+    }
+}
+
+.content code.highlight,
+.alert-content code,
+.content p code, .content li code {
+    background-color: #fff5f8 !important;
+    background-color: #fff5f8 !important;
+    background-color: #fff5f8 !important;
+}
+
+.layout.is-page .layout-side {
+    color: #3f4254;
+    background-color: #fff;
+    box-shadow: 0 0 28px 0 rgb(82 63 105 / 5%);
+}
+
+.layout.is-page .layout-user .layout-title {
+    color: #3f4254;
+}
+
+.layout.is-page .layout-footer {
+    background-color: #f8f9fa;
+    background-color: #f8f9fa;
+    background-color: #f8f9fa;
+}
+
+.layout-gotop {
+    background: #e9ecef;
+    color: #3f4254;
+}
+
+    .layout-gotop:hover {
+        background-color: #dee2e6;
+    }
+
+.tabs-body {
+    background-color: #fff;
+}
+
+.page-layout-demo-footer-link {
+    color: #3f4254;
+}
+
+.menu .nav .dropdown-menu .nav-link:not(.disabled):hover, .menu .nav .dropdown-menu .nav-link.active, .menu .submenu .nav-link.active, .menu .submenu .nav-link:not(.disabled):hover, .cascade .dropdown-item:not(.disabled):hover, .cascade .dropdown-item.active, .cascade .nav .nav-link:not(.disabled):hover, .cascade .nav .nav-link.active {
+    --bb-bg-violet: #7a5cff;
+    background-color: var(--bb-bg-violet);
+    color: var(--bs-white);
+}